The present invention relates to a method for molding a tire in which two regions of the tire are molded in successive steps with an annular reinforcement provided between the two tire regions. The present invention relates also to an apparatus for carrying out such a method.
The forces resulting from the air pressure in a tire for motor vehicles are usually taken up by diagonally or radially arranged textile or wire reinforcements. Due to these reinforcements, the production of such tires has been carried out by manual labor which entailed high cost, considerable time and also some inaccuracies during mounting and fixing of the reinforcement, resulting in low quality tires which had to be often discarded.
It has therefore been tried to produce tires for motor vehicles from plastic elastomers without any reinforcement, whereby the total forces, resulting from the air pressure within the tire and from the centrifugal force during operation of the tire, are taken up only by the elastomer. This permits an automatic production of the tire by injection molding.
The production of tires without an annular reinforcement is however connected with difficulties if such tires are formed with a height and width relationship in which this relationship differs from a 1:1 relationship, since a toroidal-shaped hollow body of relatively small and constant wall thickness tends to assume a circular cross-section when subjected to an inner air pressure.